UC Irvine

During the Northridge earthquake of 1994, many steel structures collapsed as a result of the connection failures in the structure. After investigation, it was concluded that the connections in the steel structure, including the column base connection, have to be made stronger and to be able to dissipate energy during seismic motion. To facilitate that, a new kind of damper system having Magnetorheological Elastomers (MRE) as the damping material is proposed here. MRE was taken because of its ability to dissipate energy and provide extra stiffness when needed. The damper system along with the column base connection was then modelled, and modal, harmonic and transient analyses were performed on the model using Finite Element Analysis in ANSYS. The results showed that MRE successfully decreased the moment reaction at the connection, making it more reliable during strong earthquakes. The analyses were performed with prescribed loading by SAC, and El Centro ground motion, and in both the cases the designed damper system showed its capability of dissipating energy. It was also seen that with MRE as damper, the natural frequency of the connection can also be controlled, which can prove useful in certain cases. A parametric study was then conducted to see how the effect varies with different material and physical parameters of MRE.